﻿/* ***** BEGIN LICENSE BLOCK *****
 * Version: MPL 1.1/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Mozilla Public License Version
 * 1.1 (the "License"); you may not use this file except in compliance with
 * the License. You may obtain a copy of the License at
 * http://www.mozilla.org/MPL/
 *
 * Software distributed under the License is distributed on an "AS IS" basis,
 * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
 * for the specific language governing rights and limitations under the
 * License.
 *
 * The Original Code is Mozilla XML-RPC Client component.
 *
 * The Initial Developer of the Original Code is
 * Digital Creations 2, Inc.
 * Portions created by the Initial Developer are Copyright (C) 2000
 * the Initial Developer. All Rights Reserved.
 *
 * Contributor(s):
 *   Martijn Pieters <mj@digicool.com> (original author)
 *   Samuel Sieb <samuel@sieb.net>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either the GNU General Public License Version 2 or later (the "GPL"), or
 * the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the MPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the MPL, the GPL or the LGPL.
 *
 * ***** END LICENSE BLOCK ***** */

// From: http://lxr.mozilla.org/mozilla/source/extensions/xml-rpc/src/nsXmlRpcClient.js#956

/* Convert data (an array of integers) to a Base64 string. */
const toBase64Table = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/';
const base64Pad = '=';

function toBase64(data) {
    let result = '';
    const length = data.length;
    let i;
    // Convert every three bytes to 4 ascii characters.
    for (i = 0; i < (length - 2) ; i += 3) {
        result += toBase64Table[data.charCodeAt(i) >> 2];
        result += toBase64Table[((data.charCodeAt(i) & 0x03) << 4) + (data.charCodeAt(i + 1) >> 4)];
        result += toBase64Table[((data.charCodeAt(i + 1) & 0x0f) << 2) + (data.charCodeAt(i + 2) >> 6)];
        result += toBase64Table[data.charCodeAt(i + 2) & 0x3f];
    }

    // Convert the remaining 1 or 2 bytes, pad out to 4 characters.
    if (length % 3) {
        i = length - (length % 3);
        result += toBase64Table[data.charCodeAt(i) >> 2];
        if ((length % 3) == 2) {
            result += toBase64Table[((data.charCodeAt(i) & 0x03) << 4) + (data.chartCodeAt(i + 1) >> 4)];
            result += toBase64Table[(data.charCodeAt(i + 1) & 0x0f) << 2];
            result += base64Pad;
        } else {
            result += toBase64Table[(data.charCodeAt(i) & 0x03) << 4];
            result += base64Pad + base64Pad;
        }
    }

    return result;
}

/* Convert Base64 data to a string */
const toBinaryTable = [
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
    52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, 0, -1, -1,
    -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
    15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,
    -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
    41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1
];

const base64ToString = data => {
    let result = '';
    let leftbits = 0; // number of bits decoded, but yet to be appended
    let leftdata = 0; // bits decoded, but yet to be appended

    // Convert one by one.
    for (let i = 0; i < data.length; i++) {
        const c = toBinaryTable[data.charCodeAt(i) & 0x7f];
        const padding = (data.charCodeAt(i) == base64Pad.charCodeAt(0));
        // Skip illegal characters and whitespace
        if (c == -1) continue;

        // Collect data into leftdata, update bitcount
        leftdata = (leftdata << 6) | c;
        leftbits += 6;

        // If we have 8 or more bits, append 8 bits to the result
        if (leftbits >= 8) {
            leftbits -= 8;
            // Append if not padding.
            if (!padding)
                result += String.fromCharCode((leftdata >> leftbits) & 0xff);
            leftdata &= (1 << leftbits) - 1;
        }
    }

    // If there are any bits left, the base64 string was corrupted
    if (leftbits)
        throw Components.Exception('Corrupted base64 string');

    return result;
};

startTest("dromaeo-string-base64", '09340c18');

let str = [];

for (let i = 0; i < 4096; i++)
    str.push(String.fromCharCode((25 * Math.random()) + 97));

str = str.join("");
str += str;
str += str;

let base64;

test("Convert String to Base 64", () => {
    base64 = toBase64(str);
});

prep(() => {
    if (!base64)
        base64 = toBase64(str);
});

test("Convert Base 64 to String", () => {
    if (str !== base64ToString(base64)) {
        throw "String conversion mis-match.";
    }
});

endTest();